1. Field of the Invention
The present invention relates to a magnetic recording and reproduction apparatus which is compact and lightweight and is superb in productivity.
2. Description of the Related Art
Recently, the reduction of the size, weight and production cost of magnetic recording and reproduction apparatuses has become desirable.
Hereinafter, a conventional magnetic recording and reproduction apparatus will be described.
A conventional magnetic recording and reproduction apparatus as described in Japanese Laid-Open Publication No. 11-273184 is known.
FIG. 8 is a plan view of a conventional magnetic recording and reproduction apparatus in a state where a cassette is mounted but a tape is not loaded (unloading mode). Some components are omitted from FIG. 8 for simplicity.
Reference numeral 110 represents a cassette, and reference numeral 112 represents a magnetic tape extended in the cassette 110. The magnetic tape 112 is wound around an S reel 113 and a T reel 119 accommodated in the cassette 110.
Reference numeral 118 represents a sub chassis, on which the cassette 110 is mountable. The sub chassis 118 is guided by guide sections (not shown) on both sides of a main chassis 150 and is movable in directions represented by arrows A and B.
Reference numeral 120 represents an S reel stand and reference numeral 122 represents a T reel stand, both of which are rotatably provided on the sub chassis 118. The S reel stand 120 is engageable with the S reel 113, and the T reel stand 122 is engageable with the T reel 119.
Reference numeral 124 represents a tension arm, which is provided on the sub chassis 118 so as to be pivotable about a tension arm shaft 126. A tension post 128 is provided at one end of the tension arm 124.
FIG. 9 shows the magnetic recording and reproduction apparatus shown in FIG. 8 in a tape reproduction or recording state (hereinafter, referred to as a “loading mode”). In this mode, the magnetic tape 112 is wound around the tension post 128. The tension post 128 varies the tension of the tension band 130 in accordance with the tension of the magnetic tape 112, and controls the rotation torque of the S reel stand 120 around which the tension band 130 is wound.
Reference numeral 132 represents an S boat and reference numeral 134 represents a T boat. The S boat 132 has an S1 post 136 provided thereon, and the T boat 134 has a T1 post 138 and a T2 post 140 provided thereon. In order to obtain the loading mode shown in FIG. 9, the magnetic tape 112 is pulled out from the cassette 110 along boat guide grooves 142 and 144 and wound around a cylinder 146.
Reference numeral 148 represents a pinch arm pivotably supported by the main chassis 150. A pinch roller 152 is provided at one end of the pinch arm 148.
In order to obtain the loading mode shown in FIG. 9, the pinch arm 148 is pivoted clockwise and pressure-contacts the pinch roller 152 by a pressure-contacting spring (not shown) to a capstan shaft 156 of a capstan 154 with the magnetic tape 112 sandwiched between the pinch roller 152 and the capstan shaft 156. The capstan 154 is provided on the main chassis 150.
Reference numeral 158 represents a T3 post arm, which is supported by the sub chassis 118 to be pivotable about a pivoting shaft 159.
A T3 post 160 is provided at one end of the T3 post arm 158, and a cam pin 161 is provided at the other end of the T3 post arm 158. The cam pin 161 is in engagement with a cam groove 151 formed in the main chassis 150. While the sub chassis 118 moves in the direction of arrow A to place the magnetic recording and reproduction apparatus into the loading mode shown in FIG. 9, the engagement of the cam pin 161 and the cam groove 151 pivots the T3 post arm 158 clockwise, so that the T3 post 160 at the end of the T3 post arm 158 pulls out the magnetic tape 112 from the cassette 110 and winds the magnetic tape 112 around the capstan shaft 156.
The movement of the sub chassis 118 in the directions of arrows A and B is driven by cams (not shown) provided for the elements described above by the rotation of a loading motor 151. The transformation of the magnetic recording and reproduction apparatus from the unloading mode shown in FIG. 8 to the loading mode shown in FIG. 9 is driven by the cams.
FIG. 10 is a front view of the capstan shaft 156 in the loading mode shown in FIG. 9.
The capstan 154 has the following structure. A stator 174 of a motor is secured to a housing 172, and the capstan shaft 156 provided with a rotor 176 is rotatably supported.
The housing 172 is secured to a rear wall 178 of the main chassis 150 by screws 180 (FIG. 9) in the state where the running of the magnetic tape 112 has been adjusted. The rear wall 178 is formed by drawing.
As shown in FIG. 10, the running of the magnetic tape 112 is adjusted by pivoting the housing 172 in directions represented by arrow D and E. Thus, the magnetic tape 112 can run with no possibility of being damaged.
The above-described magnetic recording and reproduction apparatus have the following problems.
When a large tension is generated in the magnetic tape 112, a large force is generated in the T3 post 160 in a direction represented by arrow F (FIG. 9). As a result, a problem occurs that the T3 post arm 158 may be easily deformed, or the T3 post 160 may be positionally deviated, easily damaging the magnetic tape 112.
While the capstan shaft 156 is pivoted in the directions of arrows D and E for adjusting the running of the magnetic tape 112, it is desirable to maintain the T3 post 160 parallel to the capstan shaft 156 in order to avoid damaging the magnetic tape 112. However, this is difficult since the capstan shaft 156 is provided on the main chassis 150 and the T3 post 160 is provided on the sub chassis 118.